The present invention relates to a display unit for receiving and displaying multiplexed motion pictures (television signals), still pictures and digital signals.
Examples of a display unit of this kind include a video text system and a teletext system. FIG. 1 shows an example of the video text system. In FIG. 1, reference numeral 1 designates an ordinary television set; 2, an antenna for receiving broadcast waves; 3, a tuner; 4, a switch; 5, a CRT (cathode-ray tube) drive circuit; 6, a CRT; 7, an adapter connected to a telephone line; and 8, the telephone line.
As is well known in the art, with the video text system, still pictures and characters can be displayed on the television set according to codes, patterns and command data transmitted over the telephone line 8. However, with the video text system, it is impossible for the television set to display data transmitted over the telephone line when it is being used for receiving and displaying ordinary television broadcast signals. Accordingly, in order to display motion pictures, still pictures and character data at the same time, it is necessary to provide two television sets.